Drilling apparatus



Sept. zz, 1942. c. E. D .TTMER 2,296,213

DRILLING APPARATUS Filed April J9, 1940 azzfy.

Patented Sept. 22, 1942 DRILLING APPARATUS Carl E. Dittmer, Michigan City, Ind., assgnor to Sullivan Machinery Company, a corporation of Massachusetts Application April 9, 1940, Serial No. 328,737

7 Claims. (Cl. Z55-47) This invention relates to drilling apparatus, and more particularly to improvements in fluid conducting means for conducting cleansing fluid to the drill bit of a rotary drilling apparatus.

An object of this invention is to provide an improved cleansing fluid conducting means for a drilling apparatus. A further object is to provide an improved conducting means for the cleansing fluid of a rotary drilling apparatus whereby the fluid is conducted to the drill bit in an improved manner. Yet another object is to provide an improved cleansing fluid conducting means for a drilling apparatus of the type wherein a rotary motor is employed for rotating the drill bit and embodying a fluid conducting tube extending axially at least substantially through the motor shaft. A further object is to provide an improved iiuid conducting tube extending at least substantially through the motor shaft, and improved packing means between the tube and motor `shaft bore whereby leakage is substantially reduced. A still further object is to provide an improved means for adjusting the packing whereby the packing may be adjusted without dismantling the drilling apparatus. Still another object is to provide an improved cleansing fluid conducting means having improved vent means whereby any leakage of fluid is drained off,

thereby reducing the possibility of leakage ofv fluid to the internal motor parts and motor shaft bearings. Other objects and advantages of the invention will, however, hereinafter more fully appear.

In the accompanying drawing there is shown for purposes of illustrationone form which the invention may assume in practice.

In this drawing:

Fig. 1 is a View in central longitudinal vertical section taken through a drilling apparatus `in which an illustrative embodiment of the invention is incorporated.

Figs. 2 and 3 are enlarged fragmentary sectional views taken in the plane of Fig. 1, showing details of the improved cleansing iiuid conducting means.

Fig. 4 is an enlarged cross sectional view taken character as that disclosed in a copending application to one Win W. Paget, Serial No. 268,792, filed April 19, 1939, now matured into Patent No.

2,288,541, patented June 30, 1942. It will be evident, however, that various features of the invention may be associated with drilling apparatus of various other types.

The drilling apparatus 2 includes a drill bit rotating motor 3 carried by a rear support-4 which, in the copending application above referred to, isa control head. The motor is herein preferably of the high speed electric type and includes a casing 5 provided with front and rear heads 6 and 'I held in assembled relation with respect to the casing by usual tie bolts 8. The motor has a usual field 9 and an armature rotor I0, the latter having a shaft I I which is supported in bearings I2, I2 suitably supported in the motor heads. Threadedly connected to the rear end of the rotor shaft II is a bearing retaining member I3, and the inner race of the rear bearing I2 is held between a member I4 engaging a shoulder on the shaft and the member I3, in the manner shown. Threaded on the forward portion of the rotor shaft Il is a collar I5 and a chuck I6, the latter receiving the shank of a hollow drill rod I'I- by which the usual drill bit is carried. The rod shank is held in position within the chuck by means of pins I8 engaged within slots on the shank. Threaded at I9 within the chuck I6 is a member 20 and the latter is connected to the rotor shaft for rotation therewith through the chuck I6. The rotor shaft has an axial bore 2l extending therethrough, and threaded within the rear end of the bore is a member 22 which has an annular flange arranged in concentricity with an annular ange on a member 23 secured to the rear motor head 1, the vannular flanges cooperating to provide a liquid seal. The member I3 also has a sleeve-like portion 24 surrounding a cylindric portion ofthe member 23 also to provide a liquid seal. These seals restrict, to a substantial extent, communication of a space 25 with a bore 26 within which the rear bearing I2 is arranged, for a -purpose to be later explained.

Now referring to the improved cleansing fluid conducting means, it will be noted that extending at least substantially through the rotor shaft bore 2l is a fluid conducting tube 2l, the latter being somewhat smaller in diameter than .the bore to provide clearance between the tube and shaft. The tube 21 is rigidly threadedly secured at 28 within a member 29 secured to the rear support 4, and the member 29 has a passage 30 for connecting the interior of the tube with a suitable source of cleansing fluid supply, herein t0 a source of liquid under pressure. The annular sealing flanges on the members I3 and 23 impede, to a substantial extent, ow of any leakage of liquid from the space 25 to the bearing receiving bore 2G, and this space 25 is connected by a passage 3| with a vent passage 32 in the rear support 4, so that any leakage of liquid to the space 25 may drain to atmosphere. The forward portion of the tube 2T is slightly reduced in cross section at 33 for a short distance, and this reduced portion passes through and has a close running iit with the bore of a bushing 345 pressed in position in the shaft bore. Arranged in an enlarged front portion 35 of the shaft bore are washers 36 and 37- having disposed therebetween suitable packing 38. Threaded in a bore 39 in the member 2l) is an adjusting plug 49 provided with a screw driver slot lll, and this plug engages the forward washer 3l. Upon adjustment of the plug ,49, the front washer 31 may be moved rearwardly within the shaft bore 35 to compress the packing 38 between the washers 36, 3l into tight sealing engagement with the exterior of the tube, thereby substantially to reduce leakage past the tube to the rotor shaft bore. The bushing 34 maintains the tube 2l central of the bore 2! and prevents compression of the packing 38 from forcing the tube laterally. rIhe shaft bore between the rear washer and the bushing 34 is vented to atmosphere through passages 42, annular space 43 surrounding the rio-tor shaft and ventV grooves lili, the latter being formed in a member 45 keyed to Vthe rotor shaft. It will thus be seen that cleansing liquid may be conducted from the passage 36 in the member 29' through the conducting tube 27 to the bore 39 of the member 2i! and thence through the hollow drill rod il to the drill bit, to clear away the cuttings' from the bottom of the drill hole. The packing 3B may be readily adjusted without dismantling the drilling apparatus, simply by removing the drill rod shank from the chuck and adjusting the plug lil byl means of a screw driver inserted within the bore cf the member 20, in an obvious manner. By the provision of the vents near the opposite ends of the fluid conducting tube any leakage of the fluid is drained to atmosphere, thereby to prevent access of liquid to the rotor shaft bearings and motor windings. It will be observed that with a tight joint between the tube 21 and the member 29 no fluid can gain access to the rear end of the bore 2i' unless it gets past the packing 38, fails to vent at 52, and Works back the full length of the motor shaft. And if there were leakage at 28 it would vent at 32, just as any leakage rearward within the armature shaft would. Obviously very certain delivery of cleansing fluid to the chuck and adequate protection of the motor windings are assured. Other uses and advantages of the invention will be clearly apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

1. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with an .axial bore, a rearwardly located support, means for conducting cleansing iluid to the drill bit comprising a fluid conducting tube secured to said rear support and extending centrally within said shaft bore, packing means carried within the forward end of said shaft bore for sealingly engaging the exterior of said tube, means at the rear end of said tube providing a space surrounding said tube, and means for venting said space to atmosphere.

2. In a drilling apparatus, the combination `comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with an axial bore, a rearwardly located support, means for conducting cleansing fluid to the drill bit comprising a fiuid conducting tube secured to said rear support and extending centrally within said shaft bore, packing means carried within the forward end of said shaft bore for sealingly engaging the exterior of said tube, means near the opposite ends of said tube providing spaces surrounding said tube, and means for venting said spaces to atmosphere.

3. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with an axial bore', a rearwardly located support, means for conducting cleansing fluid to the drill bit comprising la fluid conducting tube secured to said rear support and extending centrally within said shaft bore, the forward end of said tube terminating in adjacency to the forward end of said rotor shaft, a packing arranged within the forward end of said shaft bore for sealingly engaging the exterior of Ysaid tube, means arranged at the forward end of said shaft for adjusting said packing, means providing an annular space within said shaft bore rearwardly of said packing, and means for venting said vspace to atmosphere.

4. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor. having a rotor shaft provided with a longitudinal bore, a rearwardly located support, and means for conducting cleansing fluid to the drill bit comprising a fluid conducting tube secured to said support and extending within the shaft bore, the forward end of said tube terminating in adjacency to the forward end of said rotor shaft, a packing arranged within the forward end of said shaft bore and sealingly engaging the exterior of said tube, a bushing arranged in said shaft bore rearwardly of said packing and having a bore closely surrounding said tube and through which said tube passes, and means for venting the shaft bore between said bushing and said packing.

5. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with a longitudinal bore, a rearwardly located support, and means for conducting cleansing fluid to the drill bit comprising a fluid conducting tube secured to said support `and extending within the shaft bore, the forward end of said tube terminating in adjacency to the forward end of said rotor shaft, a packing arranged within the forward end of said shaft bore and sealingly engaging the exterior of said' tube, a bushing arranged' in said shaft bore rearwardly of said packing and having a bore closely surrounding said tube and through which said tube passes, means for venting the shaft bore between said bushing and said packing, and means at the forward end of said rotor shaft for adjusting said packing.

6. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with a lon-l gitudinal bore, a rearwardly located support, and means for conducting cleansing fluid to the drill bit comprising a fluid conducting tube secured to said support and extending within the shaft bore, the forward end of said tube terminating in adjacency to the forward end of said rotor shaft, a packing arranged within the forward end of said shaft bore and sealingly engaging the exterior of said tube, a bushing arranged in said shaft bore rearwardly of said packing land having a bore closely surrounding said tube and through which said tube passes, means for venting the shaft bore between said bushing and said packing, means at the rear end of said tube providing a space surrounding said tube, and means for venting said space.

7. In a drilling apparatus, the combination comprising a motor for rotating a drill bit, said motor having a rotor shaft provided with a longitudinal bore, a rearwardly located support, and means for conducting cleansing fluid to the drill bit comprising a fluid conducting tube secured to said support and extending within the shaft bore, a packing arranged at the forward end of said shaft and sealingly engaging the exterior of said tube, a bushing arranged within the forward end of said shaft bore rearwardly of said packing and having a bore closely surrounding said tube and through which said tube passes, means providing a space surrounding said tube between said packing and said bushing, and means for venting said space.

CARL E. DITTMER. 

